<template>
  <div class="cart">
    <h4>全部商品</h4>
    <div class="cart-main">
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <div class="cart-body">
        <ul
          class="cart-list"
          v-for="(cart, index) in cartInfoList"
          :key="cart.id"
        >
          <li class="cart-list-con1">
            <input
              type="checkbox"
              name="chk_list"
              :checked="cart.isChecked"
              @change="changeChecked(cart, $event)"
            />
          </li>
          <li class="cart-list-con2">
            <img :src="cart.imgUrl" />
            <div class="item-msg">{{ cart.skuName }}</div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{ cart.skuPrice }}.00</span>
          </li>
          <li class="cart-list-con5">
            <a class="mins" @click="minusSkuNum(cart)">-</a>
            <input
              autocomplete="off"
              type="text"
              :value="cart.skuNum"
              minnum="1"
              class="itxt"
              @input="changeSkuNum(cart, $event)"
            />
            <a class="plus" @click="addSkuNum(cart)">+</a>
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{ cart.skuNum * cart.skuPrice }}</span>
          </li>
          <li class="cart-list-con7">
            <a @click="deleteCartById(cart)" class="sindelet">删除</a>
            <br />
            <a href="#none">移到收藏</a>
          </li>
        </ul>
      </div>
    </div>
    <div class="cart-tool">
      <div class="select-all">
        <input
          class="chooseAll"
          type="checkbox"
          @change="updateAllChecked"
          :checked="isCartChecked && cartInfoList.length > 0"
        />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="deleteAllCart">删除选中的商品</a>
        <a href="#none">移到我的关注</a>
        <a href="#none">清除下柜商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">
          已选择 <span>{{ cartInfoList.length }}</span
          >件商品
        </div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{ totalPrice }}</i>
        </div>
        <div class="sumbtn">
          <!-- 声明式导航 -->
          <router-link  to="/trade"  class="sum-btn">结算</router-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { mapGetters } from "vuex";
// 使用防抖与节流
import debounce from "lodash/debounce";
import throttle from "lodash/throttle";

export default {
  name: "ShopCart",
  // 组件挂载完毕 获取购物车的数据
  mounted() {
    this.getData();
  },
  computed: {
    // 数组里的第一元素，购物车的第零项
    ...mapGetters(["CartInfo"]),

    // 购物车的数据
    cartInfoList() {
      return this.CartInfo.cartInfoList || [];
    },

    // 购物车商品总价
    totalPrice() {
      return this.cartInfoList.reduce((a, b) => a + b.skuPrice * b.skuNum, 0);
    },

    // 商品全部选中时 自动勾中全选
    isCartChecked() {
      return this.cartInfoList.filter(item=>item.isChecked == '1').length === this.cartInfoList.length;
    },
  },
  methods: {
    // 获取购物车最新数据的请求函数
    getData() {
      this.$store.dispatch("getShopCart");
    },
    // 商品修改数据加一
    async addSkuNum(cart) {
      // 整理参数
      let params = { skuId: cart.skuId, skuNum: 1 };

      // 发请求：通知服务器修改当前商品的个数
      // 修改成功后：再次获取购物车的最新数据
      try {
        await this.$store.dispatch("addOrUpdateCart", params);
        this.getData();
      } catch (error) {
        alert("失败");
      }
    },

    // 商品修改数据减一
    // 使用节流 把频繁操作变为少量操作
    minusSkuNum: throttle(async function (cart) {
      // 大于一
      if (cart.skuNum > 1) {
        // 整理参数
        let params = { skuId: cart.skuId, skuNum: -1 };

        // 修改成功后再次获取数据
        try {
          await this.$store.dispatch("addOrUpdateCart", params);
          this.getData();
        } catch (error) {
          alert("失败");
        }
      }
    }, 2000),

    // 手动输入数据
    // 使用防抖  多次触发只会执行一次
    changeSkuNum: debounce(async function (cart, e) {
      // 整理参数
      let params = { skuId: cart.skuId };

      // 计算出skuNum需携带的数据
      let userRequestValue = e.target.value * 1;
      // 用户输入完毕后进行判断
      if (isNaN(userRequestValue) || userRequestValue < 1) {
        // 非法的情况  不发生变化
        params.skuNum = 0;
      } else {
        // 正常情况
        params.skuNum = parseInt(userRequestValue) - cart.skuNum;
      }

      // 发请求修改成功后  再次获取数据
      try {
        await this.$store.dispatch("addOrUpdateCart", params);
        this.getData();
      } catch (error) {
        alert(error);
      }
    }, 500),

    // 删除某一个商品
    async deleteCartById(cart) {
      // 整理参数
      let skuId = cart.skuId;

      // 删除成功 再次获取数据
      try {
        await this.$store.dispatch("deleteCartById", skuId);

        this.getData();
      } catch (error) {
        alert("失败");
      }
    },

    // 修改某一个商品的勾选状态
    async changeChecked(cart, e) {
      // 整理参数
      let params = {
        skuId: cart.skuId,
        isChecked: e.target.checked ? "1" : "0",
      };

      // 发送请求
      try {
        await this.$store.dispatch("changeChecked", params);

        this.getData();
      } catch (error) {
        alert("失败");
      }
    },

    // 全选的业务
    async updateAllChecked(e) {
      // 获取全选的复选框勾选状态  接口需要的1/0
      let isChecked = e.target.checked ? "1" : "0";

      try {
        await this.$store.dispatch("updateAllChecked", isChecked);

        this.getData();
      } catch (error) {
        alert(error);
      }
    },

    // 删除选中的商品
    async deleteAllCart() {
      try {
        await this.$store.dispatch("deleteAllCart");
        this.getData();
      } catch (error) {
        alert("失败");
      }
    },
  },
};
</script>

<style lang="less" scoped>
.cart {
  width: 1200px;
  margin: 0 auto;

  h4 {
    margin: 9px 0;
    font-size: 14px;
    line-height: 21px;
  }

  .cart-main {
    .cart-th {
      background: #f5f5f5;
      border: 1px solid #ddd;
      padding: 10px;
      overflow: hidden;

      & > div {
        float: left;
      }

      .cart-th1 {
        width: 25%;

        input {
          vertical-align: middle;
        }

        span {
          vertical-align: middle;
        }
      }

      .cart-th2 {
        width: 25%;
      }

      .cart-th3,
      .cart-th4,
      .cart-th5,
      .cart-th6 {
        width: 12.5%;
      }
    }

    .cart-body {
      margin: 15px 0;
      border: 1px solid #ddd;

      .cart-list {
        padding: 10px;
        border-bottom: 1px solid #ddd;
        overflow: hidden;

        & > li {
          float: left;
        }

        .cart-list-con1 {
          width: 15%;
        }

        .cart-list-con2 {
          width: 35%;

          img {
            width: 82px;
            height: 82px;
            float: left;
          }

          .item-msg {
            float: left;
            width: 150px;
            margin: 0 10px;
            line-height: 18px;
          }
        }

        .cart-list-con3 {
          width: 10%;

          .item-txt {
            text-align: center;
          }
        }

        .cart-list-con4 {
          width: 12.5%;
        }

        .cart-list-con5 {
          width: 12.5%;

          .mins {
            border: 1px solid #ddd;
            border-right: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }

          input {
            border: 1px solid #ddd;
            width: 40px;
            height: 33px;
            float: left;
            text-align: center;
            font-size: 14px;
          }

          .plus {
            border: 1px solid #ddd;
            border-left: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }
        }

        .cart-list-con6 {
          width: 12.5%;

          .sum {
            font-size: 16px;
          }
        }

        .cart-list-con7 {
          width: 12.5%;

          a {
            color: #666;
          }
        }
      }
    }
  }

  .cart-tool {
    overflow: hidden;
    border: 1px solid #ddd;

    .select-all {
      padding: 10px;
      overflow: hidden;
      float: left;

      span {
        vertical-align: middle;
      }

      input {
        vertical-align: middle;
      }
    }

    .option {
      padding: 10px;
      overflow: hidden;
      float: left;

      a {
        float: left;
        padding: 0 10px;
        color: #666;
      }
    }

    .money-box {
      float: right;

      .chosed {
        line-height: 26px;
        float: left;
        padding: 0 10px;
      }

      .sumprice {
        width: 200px;
        line-height: 22px;
        float: left;
        padding: 0 10px;

        .summoney {
          color: #c81623;
          font-size: 16px;
        }
      }

      .sumbtn {
        float: right;

        a {
          display: block;
          position: relative;
          width: 96px;
          height: 52px;
          line-height: 52px;
          color: #fff;
          text-align: center;
          font-size: 18px;
          font-family: "Microsoft YaHei";
          background: #e1251b;
          overflow: hidden;
        }
      }
    }
  }
}
</style>